It can’t be hard wired, but can be plugged into a 12v source, Motability don’t specifically say where to plug it in, only that it must be plug in type. The negative is the OBD ports 12v supply is always on, so you run the risk off draing the 12v battery, which may not be wise on an EV, unless a switch is incorporated in the lead powering the dashcam. The lead should also have a fuse incorporated into it.
Fitting a dashcam to a Motability Scheme car?
If you are a Motability Scheme customer and are considering fitting a dashcam to your Scheme car, here is what you need to know:
The dashcam must be plug-in type and not hard-wired into the vehicle
It must be attached in such a way as to not cause damage to the vehicle (e.g. fixed by suckers and not permanently attached to the dashboard)
Any associated costs must be covered by you (including the purchase of the dashcam and any fitting/removal costs)
https://news.motability.co.uk/motoring/everything-you-need-to-know-about-dashcams/